TWI428382B - Colour stabilised polyolefins - Google Patents

Description

Color stabilized polyolefin

This invention relates to stabilized polyolefin compositions, more particularly, but not exclusively, to stable bioriented polypropylene films and raffia fibers.

Double oriented polypropylene (PP) films and raffia fibers represent a major part of the ultimate use of polypropylene. For these applications, PP must retain some of its properties during storage in pellet form prior to use, during extrusion, and during subsequent processing and use. The preservation of these properties can be assessed by simple measurements such as: Molten flow protection. Color stability. For example, storage stability measured by color evolution during storage.

For the purpose of achieving this preservation property, an additive is usually added to the PP, which is most typically composed of a mixture of a phenolic antioxidant and a phosphite antioxidant in a ratio of from 1/1 to 1/4. These blends, which are known commercially as B-blends, are typically, for example, from tetramethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane (Anox 20). -CAS N° 6683-19-8) phenolic antioxidant and tris(2,4-di-tert-butylphenyl) phosphite (Alkanox 240-CAS N° 31570-04-4) phosphorous acid Made from a mixture of ester antioxidants.

In the prior patent application WO 03/099918 it has been claimed that a ratio (1:10 to 1:20) is much higher than the current ratio range (1/1 to 1/4) of a mixture of phenolic antioxidants and phosphite antioxidants. It can provide advantages that are beneficial to the balance of the following, especially for the advantages of spinning: Molten flow protection. Color protection. Peroxide interaction. Gas fading resistance

The concept of this high phosphite blend is developed concurrently with other concepts developed primarily for spinning, in which other phenolic antioxidants are completely protected by other stabilizers such as, for example, benzofuranone. Or substituted with a dialkylhydroxylamine. These last proposed systems are known to be phenol-free stabilizing and have been used in demanding spinning applications.

The concept of a phenol-free system has been extended to less important applications such as bi-oriented films and raffia fibers, but in these cases, the embodiments are only by, for example, commercially known blends such as Irganox HP2225. The lactone replaces a portion of the phenolic and phosphite antioxidant mixture, wherein the Irganox HP2225 comprises 42.5% tetramethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane (CAS N° 6683-19-8) phenolic antioxidant; 42.5% tris(2,4-di-tert-butylphenyl) phosphite phosphite antioxidant (CAS N° 31570-04-4) and 15 The reaction product of 5,7-(1,1-dimethylethyl-3-hydroxy-2(3H)-benzofuranone with o-xylene (CAS N° 181314-48-7).

Studying how to extend the concept of high phosphite blends to polypropylene applications other than fibers, it has been found that phosphite-rich systems can be advantageously used in other applications, such as special polypropylene bi-oriented films ( BOPP), in which a mixture of a phenolic antioxidant and a high proportion of phosphite antioxidant provides the same amount of addition as the conventional (1/1 to 1/4) mixture, while providing better melt flow protection during processing and Good color, but provides a lower melt flow protection and better color retention than some commercially available systems where some phenolic antioxidants and phosphite antioxidants have been replaced by stabilizers such as lactones. However, such blends with high proportions of phosphite, such as lactone-containing blends, exhibit color retention during storage, as evidenced by accelerated testing conducted in a hot air oven.

Surprisingly, we have found that replacing some of the phenolic antioxidants and phosphite antioxidants in the above-described high phosphite blend with polyfunctional polar molecules can simultaneously preserve the melt flow by adding the blends Protects performance and significantly improves color retention during storage. This improvement is achieved by the color enhancement effect known during processing (see Example 1 below).

This color enhancement has been known for some time in the commercial practice of stabilizing PP with phenolic antioxidants and other secondary antioxidants (see, for example, US 3,337,495 and GB 961,480). However, this effect is due to the fact that PP, which is currently available for more than 40 years, contains a transition metal catalyst residue that is much higher than that currently available (the 5 to 1000 ppm high titanium of PP at the time is 1 or lower than the current present level). 1 to 5 ppm) (see, for example, GB 961,480 and Japanese Patent No. 63-170439). Surprisingly, we have also found that the addition of polyfunctional polar molecules is also very effective as a color reducing agent for PP and a processing stabilizer which is produced by modern polymerization techniques and which is extremely low in catalyst. The residue is characteristic. This finding has also been confirmed by LLDPE (linear low density polyethylene) and HDPE (high density polyethylene) prepared by modern polymerization techniques (see Examples 3, 4 and 5 below).

The improvement observed in this finding suggests that these polyfunctional polar molecules may partially or completely replace the phosphite antioxidant, and there may be a multiplication between the phosphite antioxidant and the polyfunctional polar species.

In particular, it has been found that the concept of the present invention is useful for any type of polyolefin which can be polymerized by a single olefin such as ethylene or propylene to form a homopolymer or a mixture of two, three or more olefins as follows. beneficial. Polypropylene block copolymer of propylene and ethylene. Polypropylene messy copolymer of propylene with ethylene or ethylene and butene. Ethylene of high density polyethylene (HDPE) or linear low density polyethylene (LLDPE) with 1-butene or 1-hexene or 1-octene or another alpha-olefin.

According to the present invention, there is provided a polyolefin composition comprising: (a) a polyolefin comprising a transition metal catalyst residue having a content of less than 5 ppm by weight of the polyolefin (except for metal cocatalyst residues) (b) a first stabilizing component, optionally selected from the group consisting of a phenolic antioxidant or a phenolic antioxidant mixture; (c) a second stabilizing component, optionally selected from the group consisting of phosphites An antioxidant or phosphite antioxidant mixture; and (d) a third stabilizing component which is also used as a color inhibitor and which is a polyfunctional alcohol, amine or guanamine or a mixture thereof, wherein (b) And at least one of (c) is present and the condition is that if the phosphite antioxidant is trilauryl phosphite, it must be used in combination with another phosphite.

In this patent specification, a metal co-catalyst residue means a metal residue derived from a co-catalyst such as, for example, aluminum derived from an alkylated co-catalyst. Although modern catalyst technology has been provided which can significantly reduce the content of transition metals such as titanium, this technique cannot be applied to the common catalyst. For example, in Examples 1 and 2 contained in this patent specification, the content of the common catalyst metal residue is 106 ppm of aluminum.

Suitably, both stabilizing components (b) and (c) are present and mixed in a ratio of from 1/1 to 1/20.

The metal element of the catalyst residue is titanium, zirconium, chromium or another transition metal element or a mixture thereof.

Stabilizing component (b) is preferably a half-blocked or low hindered phenolic antioxidant, preferably 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) )-1,3,5-three -2,4,6-(1H,3H,5H)-trione (=Lowinox 1790-CAS N° 40601-76-1) or mixed tocopherol.

Mixed tocopherols are understood to be mixtures of alpha, beta, gamma and delta tocopherols, such as, for example, vitamin E derived from natural sources, wherein the concentration of such components can be determined from the natural source (eg, from products of Cargill Corporation). ) and change.

Conventionally, the stabilizing component (b) is present in an amount of from 20 ppm to 1000 ppm, preferably from 100 to 500 ppm, by weight of the polyolefin.

Preferred stabilizing component (c) is tris(2,4-di-t-butylphenyl)phosphite (=Alkanox 240-CAS N° 31570-04-4), tris(mono-mercaptophenyl) Phosphite (=Weston 399 TNPP-CAS N° 26523-78-4) and bis(2,4-di-t-butylphenyl)neopentitol diphosphite (=Ultranox 626-CAS N ° 26741-53-7).

Conventionally, the stabilizing component (c) is present in an amount of from 50 to 2000 ppm, preferably from 250 to 1500 ppm, based on the weight of the polyolefin.

The stabilizing and color-reducing agent polyfunctional alcohol is preferably dipentaerythritol.

The stable and polyfunctional amine is preferably tri-isopropanolamine (TIPA, CAS 122-20-3).

The stable and polyfunctional guanamine is preferably 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamate)- (=Lowinox MD-24, CAS-322687-78-8). Lowinox is a trademark of Manufacturing Technology GmbH, Great Lakes (Germany), now Chemtura Manufacturing GmbH.

Conventionally, the stabilizing and coloring inhibitor component (d) is present in an amount of from 50 to 1500 ppm, preferably from 150 to 500 ppm, based on the weight of the polyolefin.

Suitably, the polyolefin composition of the present invention comprises a fourth stable composition (e) which is a hindered amine stabilizer.

The stable composition (e) is preferably selected from at least one of the following: dimethyl succinate polymer containing 4-hydroxy-2,2,6,6-tetramethyl-1-piperidineethanol (Lowilite) 62-CAS N° 65447-77-0), poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-three -2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imido]-1,6-hexanediyl[(2,2,6,6- Tetramethyl-4-piperidinyl)imido]](Lowilite 94-CAS N° 71878-19-8) or 1,3,5-three -2,4,6-triamine, N,N'''-1,2-ethanediylbis[N-[3-[[4,6-bis[butyl(1,2,2,6, 6-pentamethyl-4-piperidinyl)amino]-1,3,5-three -2-yl]amino]propyl]-N',N''-dibutyl-N',N''-bis(1,2,2,6,6-pentamethyl-4-piperidine Base)-(Lowilite 19-CAS 106990-43-6). Lowilite is the company of Great Lakes (Germany) Manufacturing GmbH, now a trademark of Chemtura Manufacturing GmbH.

Conventionally, the stabilizing component (e) is present in an amount of from 50 to 3000 ppm, preferably from 200 to 2000 ppm, based on the weight of the polyolefin.

Suitably, the polyolefin of the invention comprises an acid scavenger as component (f).

The acid scavenger component (f) is preferably a metal oxide, a salt of a fatty acid and a light metal such as calcium stearate, zinc stearate, magnesium stearate or hydrotalcite or a mixture thereof.

Conventionally, the acid scavenger component (f) is present in an amount of from 50 to 3000 ppm, preferably from 300 to 1500 ppm, based on the weight of the polyolefin.

The total amount of components (b), (c), (d), (e) and (f) is preferably present in an amount of from 500 to 5000 ppm, preferably from 1000 to 3000 ppm, by weight of the polyolefin.

Suitably, the polyolefin is polypropylene or polyethylene.

In the case where the polyolefin is polypropylene and the transition metal catalyst residue is a polyolefin composition of vanadium, the polymer (other than the metal co-catalyst residue) contains less than 0.5 ppm vanadium.

The invention also relates to articles made from the polyolefin compositions described and claimed herein.

A mixture of the following materials has been found by further optimizing the additive blend of the present invention to achieve the same melt flow protection as that achieved with a blend containing a lactone. Phenolic antioxidants. Phosphite antioxidants. Polyfunctional polar molecules, generally polyfunctional alcohols. And HAS-hindered amine stabilizers, as appropriate, as described in WO 03/099918. And a suitable acid scavenger can provide a new composition that is highly balanced by: Molten flow protection. Color protection during processing. Color retention during storage

In particular, an improved combination of this property can be used, inter alia, in polypropylene applications involving orientation or large deformation, particularly in films, bi-oriented films, raffia fibers, and thermoformed sheets. It can also be used in other applications based on the same formulation used for commercial manufacturing reasons, such as in pipe extrusion, blow molding, and injection molding.

The phenolic antioxidant (component (b)) may be selected from the group consisting of: Highly hindered phenol, preferably (but not limited to): tetramethylene (3,5-di-t-butyl-4-hydroxyhydrocinnamate) methane (Anox 20-CAS N° 6683-19-8 3-(3',5'-di-tert-butyl-4'-hydroxyphenyl)propanoic acid octadecyl ester (Anox PP18-CAS N° 2082-79-3); 3-(3', C9-C11 linear and branched alkane esters of 5'-di-t-butyl-4'-hydroxyphenyl)propionic acid (Irganox 1135-CAS N°); C13-C15 linear and branched alkane esters of 3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionic acid (Anox 1315-CAS N ° 171090-93-0); 2,2'-thiodiethyl bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] (Anox 70-CAS N ° 41484-35-9); 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)trimeric isocyanate (Anox IC14-CAS N° 27676-62-6) ;1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene (Anox 330-CAS N° 1709-70-2 N,N'-hexamethylene-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propanamide] (Lowinox) HD98-CAS N° 23128-74-7); 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamate) (Lowinox MD24-CAS N° 32687-78-8). The mixture is also suitable.

. Or a lower hindered phenol, a phenol with a high degree of steric hindrance with some steric hindrance but not more common antioxidants based on 2,6-di-t-butylphenol. An example is 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-three -2,4,6-(1H,3H,5H)-trione (Lowinox 1790-CAS N° 40601-76-1); 2,2'-methylenebis(6-tert-butyl-4-methylphenol) (Lowinox 22 M46-CAS N° 119-47-1); 4,4'-butylidene bis(2-tert-butyl-5-methylphenol) (Lowinox 44B25-CAS N° 85-60-9); 2,2'-isoisobutyl bis(4,6-dimethylphenol) (Lowinox) 22IB46-CAS N° 33145-10-7); and 1,1,3-tris(2'-methyl-4'-hydroxy-5'-tert-butylphenyl)butane (Lowinox) CA22-CAS N° 1843-03-4); 2,5-di-triplylhydroquinone (Lowinox) AH25-CAS N° 79-74-3); 2,2'-methylene-bis(4-methyl)-6-(1-methylcyclohexyl)phenol (Lowinox WSP-CAS N° 77-62-3); 4,4'-thiobis(2-tert-butyl-5-methylphenol) (Lowinox TBM6-CAS N° 96-69-5); 2,2'-thiobis(6-tert-butyl-4-methylphenol) (Lowinox) TBP6-CAS N° 90-66-4) and triethylene glycol bis[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (Lowinox GP45-CAS N° 36443-68-2), synthetic alpha-tocopherol (CAS N° 10191-41-0) and mixed tocopherols as found in vitamin E. The mixture is also suitable. Irganox Is a trademark of Ciba Specialty Chemicals Holding.

Although various types of phenolic antioxidants can be used in the present invention, the desired effect of the lower hindered phenol is more remarkable.

The phosphite antioxidant (component (c)) is preferably, but not limited to, at least one selected from the group consisting of tris(4-n-decylphenyl)phosphite (TNPP-CAS N° 26523) -78-4), tris(mono-nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl)phosphite (Alkanox 240-CAS N° 31570-04-4) , di-octadecyl neopentyl alcohol diphosphite (Weston 618-CAS N° 3806-34-6), bis(2,4-di-t-butylphenyl)neopentitol diphosphoric acid Ester (Ultranox 626, Alkanox P-24-CAS N° 26741-53-7), tetrakis(2,4-di-t-butylphenyl) 4,4'-extended biphenyl diphosphinate ( Alkanox 24-44-CAS N° 38613-77-3), 2,4,6-tri-t-butylphenyl-2-butyl-2-ethyl-1,3-propanediol phosphite (Ultranox 641-CAS 161717-32-4), bis(2,4-diisopropylphenylphenyl)neopentanol diphosphite (Doverphos 9228-CAS N° 154862-43-8).

Suitably, the phosphite antioxidant is free of sulfur phosphite.

The polyfunctional alcohol is preferably, but not limited to, selected from the following: Polyethylene glycol of the general formula H{O(CH ₂ ) _m } _n -OH, generally diethylene glycol, triethylene glycol or tetraethylene glycol. Polyhydric alcohols such as glycerol, butanediol, pentaerythritol, dipentaerythritol or sorbitol. An oligomer or polymer obtained by oligomerization or polymerization of a polyol, such as, for example, polypentaerythritol.

HAS-(hindered amine stabilizer) (component (e)) is preferably, but not limited to, at least one selected from the group consisting of 4-hydroxy-2,2,6,6-tetramethyl- 1-piperidineethanol dimethyl succinate polymer (Lowilite 62-CAS N° 65447-77-0), poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-three -2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imido]-1,6-hexanediyl[(2,2,6,6- Tetramethyl-4-piperidinyl)imido]](Lowilite 94-CAS N° 71878-19-8) or N,N'''-1,2-ethanediylbis[N-[3-[[4,6-bis[butyl(1,2,2, 6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-three -2-yl]amino]propyl]-N',N''-dibutyl-N',N''-bis(1,2,2,6,6-pentamethyl-4-piperidine Base)-1,3,5-three -2,4,6-triamine (Lowilite 19-CAS 106990-43-6).

Further examples of components (b), (c) and (e) suitable for use in the present invention are included in the list of phenolic antioxidants, phosphite antioxidants and HAS as mentioned in EP-A1-1 338 622. .

General description of the following examples of stabilizer blends of the invention prepared from polypropylene or polyethylene powder A) The mixing of the additives may be a mixture of a phenolic antioxidant, a phosphite antioxidant, a hindered amine antioxidant, an acid scavenger, a polyfunctional alcohol and other additives, and a polyolefin such as a polypropylene or polyethylene powder. It is done as follows and is highly dependent on the physical form of the stabilizers. These additives may be in the form of a powder, a liquid, and a non-powder blend (NDB).

1. Additive in powder form: 50% of the polyolefin, such as polypropylene or polyethylene powder, is weighed into a plastic bag, and the additive powder is separately weighed and added to the polyolefin in the bag, such as polypropylene powder or poly In vinyl powder. The remaining polyolefin, such as polypropylene powder or polyethylene powder, is then added and the bag is inflated with nitrogen and shaken in different directions for at least 2 minutes.

2. Additives in liquid form: as described in Section 1 above, 50% of the polyolefin, such as polypropylene or polyethylene powder, is weighed into a plastic bag, and then a small amount of polyolefin, such as polypropylene or polyethylene (which It is weighed into the aluminum pan from the total amount of polyolefin, such as polypropylene or polyethylene. In a tray containing a polyolefin such as polypropylene powder or polyethylene powder, the correct amount of liquid additive is added via a pipette and mixed with a polyolefin such as polypropylene powder or polyethylene powder for about 10 minutes (or Until a uniform powder mixture is formed). Then, the contents of the aluminum pan are added to the polyolefin in the plastic bag, such as polypropylene powder or polyethylene powder, and the remaining polyolefin, such as polypropylene powder or polyethylene powder, is added and the bag is inflated with nitrogen. Shake in different directions for at least 2 minutes.

3. Additives in the form of NDB: NDB (non-powder blend) blends are prepared from additive pre-blends containing no polymeric carrier according to U.S. Patent No. 5,240,642 and European Application No. EP-A1-0 514 784. . Similar blends are available from alternative suppliers as what is referred to as a 'package'.

When the additives are in this particular physical form, the NDB or 'a pack' is first ground in a mortar and pestle. The additives and the polyolefin, such as polypropylene powder or polyethylene powder, may be mixed according to the method described in the above section 1.

B) Processing of the additive/polyolefin, such as polypropylene powder or polyethylene powder mixture

After shaking the plastic bag for 2 minutes, the mixture was poured into a funnel of a Brabender single screw extruder (compression ratio 3:1, L/D 25, helix diameter 19 cm, spiral speed 60 rpm).

The mixture was extruded on a Brabender single screw extruder with the following settings: - Temperature profile for PP: 200-215-235-250 ° C - Temperature profile for LLDPE and HDPE: 175-175-180-190 °C - 1 extrusion under a nitrogen blanket

Collect each strand and make a pill. This first extrusion operation is called a mixing operation or a zero point operation.

To evaluate the performance of the different additive formulations, the following set of compounds after extrusion zero operation was performed on a Brabender single screw extruder: - Temperature profile for PP: 200-225-250-275 ° C - for LLDPE and HDPE Temperature profile: 200-210-220-230 ° C - 5 extrusion operations in open air - after each extrusion operation, the individual strands were collected and pelletized. The pellets after the first, third and fifth extrusion operations were collected for further measurement (color measurement, melt flow measurement), whereas the oven aging performance was measured after the second extrusion operation. Got it.

C) Performance testing of different formulations

The yellowing index (YI) of the pellets collected after the first, third, and fifth extrusion operations was measured to determine the color stability of the formulation. The yellowing index is measured according to the standard ASTM E313.

Further, the melt flow (MFI) of the pellets collected after the first, third, and fifth extrusion operations was measured to determine the processing stability of the formulation. The melt flow is measured according to standard ISO 1133.

. For PP, at 230 ° C and 2.16 kg load. For LLDPE and HDPE, respectively, at 190 ° C and 10 kg and 21.6 kg load. The load selected for these two polymers is not commonly used, but better experimental accuracy is achieved.

The storage stability of the pellets collected after the second extrusion operation was measured by exposing them to a hot air oven for several days and then measuring the YI.

Example 1

Example 1 relates to an additive formulation in a PP resin obtained by a gas phase polymerization to obtain a titanium catalyst residue of 3.3 ppm.

Mixing, processing and testing of the formulations are carried out as generally described above.

2000ppm total load. Formulation 1: 500 ppm calcium stearate + 500 ppm Anox 20 + 1000 ppm Alkanox 240 (= B-blend reference). Formulation 2: 500 ppm calcium stearate + 1500 ppm Irganox HP 2225 (= stabilization with lactone as matrix). Formulation 3: 500 ppm calcium stearate + 150 ppm Lowinox 1790+1350ppm Alkanox 240 (=high phosphite formulation according to WO 03/099918 patent). Formulation 4: 500 ppm calcium stearate + 100 ppm Lowinox 1790+900ppm Alkanox 240+500ppm dipentaerythritol (=preparation according to the invention)

As can be seen from Tables 1 and 2, the high phosphite formulation (Formulation 3) can replace the current formulation (B-blend, such as Formulation 1) to provide better molecular protection and a significantly better color after processing. However, the molecular protection system is not as good as that of the lactone-containing formulation (Formulation 2), but the color protection system is far better. Substituting a portion of the high phosphite formulation (Formulation 3) with dipentaerythritol achieves the same molecular protection, but is much better protected.

As can be seen from Tables 3 and 4, the formulation containing the lactone (Formulation 2) and the formulation containing the high amount of phosphite (Formulation 3) have poor aging aging properties, but can be used to dimethylene The alcohol replaced a portion of the high phosphite formulation (formulation 3) to achieve a significant improvement.

It is also noted that the improvement obtained by substituting a portion of the high phosphite formulation (formulation 3) with dipentaerythritol is more effective as the temperature increases as shown in the following table.

Example 2

Example 2 relates to an additive formulation of the present invention in a PP resin obtained by a gas phase polymerization to obtain a titanium catalyst residue of 3.3 ppm.

Mixing, processing and testing of the formulations are carried out as generally described above.

1700ppm total load. Formulation 5: 500 ppm calcium stearate + 400 ppm Anox 20 + 800 ppm Alkanox 240 (= common B-blend formulation). Formulation 6: 500 ppm calcium stearate + 1200 ppm Irganox HP 2225 (= stabilization with lactone as matrix). Formulation 7: 500 ppm calcium stearate + 250 ppm Lowinox 1790 + 700 ppm Alkanox 240 + 250 ppm dipentaerythritol (= formulation according to the invention)

As shown in Tables 6 and 7 above, the optimum formulation for BOPP application (Formulation 7) according to the present invention can maintain control of the melt flow index more than the lactone-based formulation (Formulation 6). Good and therefore better control of the procedure and far better control than current formulations (Formulation 5) to provide optimal color protection at the same time.

In addition, as can be seen from Tables 8 and 9, this optimized formulation provides excellent color protection during storage at moderately high temperatures (50 ° C), but does not consistently retain this advantage at higher temperatures (120 ° C).

The difference in aging performance observed between Formulation 4 of Example 1 and Formulation 7 of Example 2 at elevated temperatures (120 ° C) may be attributed to the facts shown in Table 10 below: The total amount of tetraol and phosphite is much higher than the latter

Example 3

Example 3 relates to an additive formulation of the present invention which was polymerized in a loop slurry process to give a chromium catalyst residue of 3.5 ppm HDPE resin (density of 0.955 g/cc and comonomer of 1-hexene).

Mixing, processing and testing of the formulations are carried out as generally described above.

. Formulation 8: 500 ppm zinc stearate + 400 ppm Anox 20 + 800 ppm Alkanox 240 (= standard B-blend formulation of this type of polymer). Formulation 9: 500 ppm zinc stearate + 200 ppm Lowinox 1790 + 800 ppm Alkanox 240 (based on high performance semi-hindered phenolic antioxidant matrix). Formulation 10: 500 ppm zinc stearate + 200 ppm Lowinox 1790 + 500 ppm Alkanox 240 + 300 ppm dipivalaerythritol (preparation according to the invention). Formulation 11: 500 ppm zinc stearate + 200 ppm Lowinox 1790 + 500 ppm Ultranox 626 (a high performance semi-hindered phenolic antioxidant and high performance phosphite based formulation). Formulation 12: 500 ppm zinc stearate + 200 ppm Lowinox 1790 + 350 ppm Ultranox 626 + 300 ppm dinepentaerythritol (= formulation according to the invention)

For the current phosphite (Alkanox 240), the melt index measured in grams/10 minutes under both 10 and 21.6 kg loads is summarized in the table below:

The color change measured by the particles containing the current phosphite (Alkanox 240) is summarized in the following table as measured by YI:

Comparison of Formulations 9 and 10 shows that a combination of good melt flow protection and significantly better color can be obtained by replacing 300 ppm of phosphite Alkanox 240 with an equivalent amount of dipentaerythritol. On the other hand, a comparison between formulations 8 and 10 shows that formulation 10 is superior to standard B-blend formulation 8 in terms of melt flow protection and color retention in accordance with the present invention.

For the comparison of high performance phosphite (Ultranox 626) with current phosphite (Alkanox 240), the melt index measured in grams/10 minutes under both 10 and 21.6 kg loads is summarized in the table below:

Moreover, the color variations measured by the particles are summarized in the following table:

Comparison of Formulations 9 and 11 demonstrates that even at lower levels, high performance phosphites have an effect on melt flow protection and color protection. Conversely, a comparison of Formulations 11 and 12 illustrates how the present invention further reduces high performance sub- The amount of phosphate used to provide both superior melt flow protection and color retention.

The oven aging effect as measured by the YI of the injection molded sheet at 50 ° C is summarized in the following table:

This clearly shows the advantages of the formulations (10 and 12) based on the discovery of the present invention.

Example 4

Example 4 relates to a LippE resin having a titanium catalyst residue of 2.5 ppm in a gas phase reactor supported by Ziegler-Natta catalyst supported on vermiculite (density of 0.920 g/cm 3 , comonomer of 1- Additive formulations of the invention in butene).

Mixing, processing and testing of the formulations are carried out as generally described above.

. Formulation 13: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 800 ppm TNPP (= formulation with low hindered phenolic antioxidant as matrix). Formulation 14: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 300 ppm TNPP + 300 ppm TIPA (preparation according to the invention). Formulation 15: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 300 ppm TNPP + 300 ppm dipentaerythritol (preparation according to the invention)

The melt index measured in grams per 10 minutes under both 10 and 21.6 kg loads is summarized in the table below:

Moreover, the color variations measured by the particles are summarized in the following table:

For this resin, the competition between the cross-linking and the chain-cutting decomposition mechanism makes the change in the melt index value difficult to explain. All three formulations used showed good melt flow protection.

However, in terms of color, a comparison between Formulations 13 and 14 showed that 300 ppm TPA was replaced with 300 ppm TIPA initially to obtain significantly better color and this advantage was retained in multiple manipulation experiments. On the other hand, a comparison between formulations 13 and 15 showed that replacing 300 ppm of TNPP phosphite with 300 ppm of diheptaerythritol initially gave better color and retained this advantage in multiple operation experiments. However, for this type of resin and phosphite, the results obtained with TIPA are superior to those obtained with dipentaerythritol.

The oven aging effect as measured by the YI of the injection molded sheet at 100 ° C is summarized in the following table:

Example 5

Example 5 relates to the polymerization of a metallocene catalyst supported on vermiculite in a gas phase reactor to obtain a LLDPE resin having a zirconium catalyst residue of less than 0.2 ppm (density of 0.918 g/cm 3 , comonomer of 1- Additive formulations of the invention in hexene).

Mixing, processing and testing of the formulations are carried out as generally described above.

. Formulation 16: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 800 ppm TNPP (= formulation with low hindered phenolic antioxidant as matrix). Formulation 17: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 300 ppm TNPP + 300 ppm TIPA (= formulation according to the invention). Formulation 18: 500 ppm zinc stearate + 100 ppm mixed tocopherol + 300 ppm TNPP + 300 ppm dipentaerythritol (= formulation according to the invention)

The melt index measured in grams per 10 minutes under both 10 and 21.6 kg loads is summarized in the table below:

A comparison of the melt flow index measured from formulations 16 and 17 shows that replacing the 300 ppm TNPP phosphite with the same amount of TIPA effectively protects the melt flow. On the other hand, the replacement of 300 ppm TNPP phosphite with the same amount of dipentaerythritol does not fall into this situation, which does not achieve the same degree of protection.

The color changes obtained from the particles are summarized in the table below:

Here, it is again observed that the color is increased by TIPA or dipentaerythritol.

Example 6

Example 6 relates to an additive formulation of the present invention prepared by using different polymerization techniques and different catalysts in a PP resin. To simplify the study, phosphites were not included in the formulations listed in this test.

Different PP systems used: PP1: Unipol (Trademark of DOW Chemical Co., Ltd.) A polypropylene homopolymer having a transition metal catalyst residue of 1.3 ppm titanium produced by a gas phase polymerization technique.

. PP2: Spheripol (Trademark of Basell Holding BV) A polypropylene homopolymer having a transition metal catalyst residue of 0.5 ppm titanium as a whole polymerization technique.

. PP3: Novolen (Trademark of Novolen Technology Holding CV) A polypropylene homopolymer having a transition metal catalyst residue of 1.4 ppm titanium produced by a gas phase polymerization technique.

Mixing, processing and testing of the formulations are carried out as generally described above.

. Formulation 19: 500 ppm zinc stearate + 250 ppm 2,2'-isobutylene bis(4,6-dimethylphenol) (=Lowinox 22IB46-CAS N° 33145-10-7). Formulation 20: 500 ppm zinc stearate + 250 ppm 2,2'-isobutylene bis(4,6-dimethylphenol) (=Lowinox 22IB46-CAS N° 33145-10-7) +250ppm dipentaerythritol. Formulation 21: 500 ppm zinc stearate + 250 ppm mixed tocopherol. Formulation 22: 500 ppm zinc stearate + 250 ppm mixed tocopherol + 250 ppm

Dipentaerythritol using Lowinox The results observed at 22IB46 are summarized in the table below:

The results observed with mixed tocopherols are summarized in the table below:

These results show that the addition of diheptaerythritol to polypropylene, which is characterized by low transition metal catalyst residue content and stabilized only by low hindered phenolic antioxidants, has no or even some melt flow protection for the three systems tested. Micro-negative, but has a strong influence on color. When the previous examples show that replacing the same amount of phosphite with the same amount of dipentaerythritol can achieve better melt flow protection and better protection at the same time, this suggests that dipentaerythritol should be good for phosphite. Synergist.

Claims (29)

A polyolefin composition comprising: (a) a polyolefin comprising a transition metal catalyst residue in an amount of less than 5 ppm by weight of the polyolefin, in addition to a metal co-catalyst residue; (b) a first stabilizing component consisting of a phenolic antioxidant or a phenolic antioxidant mixture; (c) a second stabilizing component consisting of a phosphite antioxidant or a phosphite antioxidant mixture; (d) a third stabilizing component which is also used as a color inhibitor and which is a polyfunctional alcohol, an amine or a guanamine or a mixture thereof, with the proviso that if the phosphite antioxidant is trilauryl phosphite, It must then be used in combination with another phosphite; and wherein the stabilizing components (b) and (c) are mixed in a ratio between 1/1 and 1/20. The polyolefin composition of claim 1, wherein the metal element of the catalyst residue is titanium, zirconium, chromium or another transition metal element. The polyolefin composition of claim 1, wherein the metal element of the catalyst residue is titanium, zirconium, chromium or a mixture thereof. The polyolefin composition of claim 1 or 2 wherein the stabilizing component (b) is a low or semi-hindered phenolic antioxidant. The polyolefin composition of claim 1 or 2, wherein the stabilizing component (b) is 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzene Methyl)-1,3,5-three -2,4,6-(1H,3H,5H)-trione or mixed tocopherol. Such as the polyolefin composition of claim 1 or 2, wherein the stability Component (b) is present in an amount from 20 ppm to 1000 ppm by weight of the polyolefin. The polyolefin composition of claim 1 or 2, wherein the stabilizing component (b) is present in an amount of from 100 to 500 ppm by weight of the polyolefin. The polyolefin composition of claim 1 or 2, wherein the stabilizing component (c) is tris(mono-nonylphenyl) phosphite, tris(2,4-di-t-butylphenyl) Phosphite or bis(2,4-di-tert-butylphenyl)neopentitol diphosphite. The polyolefin composition of claim 1 or 2, wherein the stabilizing component (c) is present in an amount of from 50 to 2000 ppm by weight of the polyolefin. The polyolefin composition of claim 1 or 2, wherein the stabilizing component (c) is present in an amount of from 250 to 1500 ppm by weight of the polyolefin. The polyolefin composition according to claim 1 or 2, wherein the third stabilizing component (d), which is also a color inhibitor, is a polyfunctional alcohol, neopentyltetraol, and a polyfunctional amine tri-isopropanol. Amine or polyfunctional guanamine 1,2-bis(3,5-di-t-butyl-4-hydroxyhydrocinnamate)- . The polyolefin composition of claim 1 or 2 wherein component (d) is present in an amount of from 50 to 1500 ppm by weight of the polyolefin. The polyolefin composition of claim 1 or 2 wherein component (d) is present in an amount of from 150 to 500 ppm by weight of the polyolefin. A polyolefin composition according to claim 1 or 2, which comprises a fourth stable composition (e) which is a hindered amine stabilizer. The polyolefin composition of claim 14, wherein the stable composition (e) is at least one selected from the group consisting of 4-hydroxy-2,2,6,6-tetramethyl-1-piperidyl Dimethyl succinate polymer, poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-three -2,4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imido]-1,6-hexanediyl[(2,2,6,6- Tetramethyl-4-piperidinyl)imido]] or N,N'''-1,2-ethanediylbis[N-[3-[[4,6-bis[butyl(1, 2,2,6,6-pentamethyl-4-piperidinyl)amino]-1,3,5-three -2-yl]amino]propyl]-N',N"-dibutyl-N',N"-bis(1,2,2,6,6-pentamethyl-4-piperidinyl) -1,3,5-three -2,4,6-triamine. The polyolefin composition of claim 14 or 15, wherein the stable composition (e) is present in an amount of from 50 to 3000 ppm by weight of the polyolefin. The polyolefin composition of claim 14 or 15, wherein the stable composition (e) is present in an amount of from 200 to 2000 ppm by weight of the polyolefin. A polyolefin composition as claimed in claim 1 which comprises an acid scavenger as component (f). The polyolefin composition of claim 18, wherein the acid scavenger component (f) is a metal oxide, a salt of a fatty acid and a light metal, or a hydrotalcite or a mixture thereof. The polyolefin composition of claim 19, wherein the salt of the fatty acid and the light metal as the acid scavenger component (f) is selected from the group consisting of calcium stearate, zinc stearate, and magnesium stearate. The polyolefin composition of claim 18 or 19, wherein the acid scavenger component (f) is from 50 to 3000 ppm by weight of the polyolefin. The quantity exists. The polyolefin composition of claim 18 or 19, wherein the acid scavenger component (f) is present in an amount of from 300 to 1500 ppm by weight of the polyolefin. The polyolefin composition of claim 18, wherein the total amount of the components (b), (c), (d), (e) and (f) is from 500 to 5000 ppm by weight of the polyolefin. The amount exists. The polyolefin composition of claim 18, wherein the total amount of the components (b), (c), (d), (e) and (f) is from 1000 to 3000 ppm by weight of the polyolefin. The amount exists. The polyolefin composition of claim 21, wherein the total amount of the components (b), (c), (d), (e) and (f) is from 500 to 5000 ppm by weight of the polyolefin. The amount exists. The polyolefin composition of claim 21, wherein the total amount of the components (b), (c), (d), (e) and (f) is from 1000 to 3000 ppm by weight of the polyolefin. The amount exists. The polyolefin composition of claim 1 or 2, wherein the polyolefin is polypropylene or polyethylene. The polyolefin composition of claim 1 or 2, wherein the polyolefin-based polypropylene and the transition metal catalyst residue comprise less than 0.5 ppm of vanadium in addition to the metal co-catalyst residue. An article made from the polyolefin composition as claimed in any one of claims 1 to 28.